What's your plan of attack? Is the core 3/4"? My initial thought was use to pre coat the new piece of marine ply with a few coats, then glue down with thickened epoxy - sort of like tile flooring. Not sure if I'd even need to lay any glass? Thought about using Coosa, but not sure I need to go to that expense.

This, I'm hoping, will be a lot easier than my last large repair. I replaced some soft wood that was on the underside of the anchor locker deck on my Sundancer. BUT, I did it w/o removing the top skin so all the work was done through the anchor locker hatch and upside down, backwards, twisted and contorted! It came out nice and in the end, I decided to put some fake teak up there (Actually, really nice!) so if I would of thought of that first, I could of skinned it!

Yeah, I know what you mean about the mix ratio if you're doing it drop by drop. One or two drops one way or the other (depending on ambient temp) can make a big difference.

As you may have figured out by now, if you're mixing large batches of epoxy (or just in a container that keeps the epoxy in higher volume) it kicks really fast. A trick is to mix it up, then spread it out thin. If it stays in the container, it retains the heat thus causing it to kick quickly. You can spread it out on the working piece, or even a scrap of something. Anything will work - just as long as it's not contained too much.

If you're using the West system, they make not only a slow hardener, but also an extra slow hardener and both will give a noticeably longer working time. As it's getting colder outside, that will help, too.

Oh... another way around having to put screws (from the deck hatch) into wood... You can overdrill the pilot hole to about 2-3 times the size of the screw. Then, come back and fill it with epoxy. Then redrill your pilot hole - this way you are only screwing into epoxy. If the hole would end up being so large that it would be visible on the floor side, only drill out the wood side.

Sorry - I wasn't very clear. I did see that way - was just offering another way. Depending on the current thickness, adding that extra layer of glass (like you mentioned), is a good idea. In reality, it probably doesn't matter too much as it isn't in a real high stress load area, unless the current holes have gotten a little enlarged.